Carbon blacks are generally produced in a furnace-type reactor by pyrolyzing a hydrocarbon feedstock with hot combustion gases to produce combustion products containing particulate carbon black.
Carbon blacks are generally characterized on the basis of analytical properties including, but not limited to, surface area, surface chemistry, aggregate size, and particle size. The properties of carbon blacks are analytically determined by tests known to the art, including, for example cetyl-trimethyl ammonium bromide absorption value (CTAB), dibutyl phthalate adsorption value of the crushed carbon black (CDBP) and Tinting strength value (TINT). Carbon blacks may also be characterized by Skewness D.sub.c and Skewness P.sub.s. "Skewness" measures the degree of asymmetry of data around the sample mean. The skewness of the distribution of the values of D.sub.c (Skewness D.sub.c) and the skewness of the distribution of the values of P.sub.s (Skewness P.sub.s) are determined by known techniques that are described herein.
Carbon blacks may be utilized as pigments, fillers, reinforcing agents and for a variety of other applications. For example, carbon blacks are widely utilized as fillers and reinforcing pigments in the compounding and preparation of rubber and plastic compounds. More particularly, carbon blacks are effective in the preparation of rubber vulcanizates intended for usage in preparing tires.
It is generally understood that the properties of a carbon black affect the properties of rubber or plastic compounds containing the carbon black. Thus, the properties of a carbon black will affect the properties of rubber tire tread compounds that incorporate the carbon blacks.
It is generally desirable in the production of tires to utilize carbon black containing tire tread compounds which have satisfactory abrasion resistance and hysteresis. The greater the abrasion resistance of a tire, the greater the number of miles the tire will last before wearing out. The hysteresis of a rubber compound means the energy dissipated under a deformation cycle. Tire tread compounds with lower hysteresis values will have reduced rolling resistance which results in reduced fuel consumption by the vehicle utilizing the tire. The rebound of a rubber compound refers to the compound elasticity. In comparison with generally utilized compounds, tire tread compounds with higher rebound values will have reduced rolling resistance and lower heat build-up. Thus, for all of these reasons, it is particularly desirable to produce carbon blacks capable of imparting greater abrasion resistance and lower hysteresis to tire compounds.
Accordingly, an object of the present invention is the production of new carbon blacks which impart increased abrasion resistance, lower hysteresis and higher rebound to natural rubbers, synthetic rubbers and blends of natural and synthetic rubbers incorporating the carbon blacks.
Another object of the present invention is new rubber compounds, advantageous for use in all season tires, touring tires and high performance tires for passenger vehicles and for use in light and medium truck tires.
Other objects of the present invention will become apparent from the following description and the claims.